Editing TACACS (section)

{{Short description|Computer network protocol}}
'''Terminal Access Controller Access-Control System''' ('''TACACS''', {{IPAc-en|'|t|ae|k|ae|k|s}}) refers to a family of related [[Authentication protocol|protocols]] handling remote authentication and related services for network access control through a centralized server. The original '''TACACS''' protocol, which dates back to 1984, was used for communicating with an authentication server, common in older [[Unix|UNIX]] networks including but not limited to the [[ARPANET]], [[MILNET]] and BBNNET. It spawned related protocols:
* '''Extended TACACS''' ('''XTACACS''') is a proprietary extension to TACACS introduced by [[Cisco Systems]] in 1990 without backwards compatibility to the original protocol. TACACS and XTACACS both allow a remote access server to communicate with an authentication server in order to determine if the user has access to the network. 
* '''TACACS Plus''' ('''TACACS+''') is a protocol developed by Cisco and released as an open standard beginning in 1993. Although derived from TACACS, TACACS+ is a separate protocol that handles [[AAA protocol|authentication, authorization, and accounting (AAA)]] services. TACACS+ has largely replaced its predecessors.